Electric signal apparatus



2 Sheets-Sheet -1. J. W; LATTIG- ELECTRIC SIGNAL APPARATUS.

Patented Aug, 1, 1893. Q

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J. W. LATTIG. ELECTRIC SIGNAL APPARATU$.

No. 502,626. Patentedikug. 1, 1893.

UNITED STATES PATENT OFFICE.

JACOB WILLIAM LATTIG, OF EASTON, PENNSYLVANIA.

ELECTRIC SIGNAL APPARATUS.

SPECIFICATION forming part of Letters Patent No. 502,626, dated August1, 1893.

Application filed June 14,1893. Serial No. 477,571. (No model.)

To aZZ whom, it may concern- Be it known that I, J ACOB WILLIAM LAT-TIG, of Easton, in the State of Pennsylvania, have invented a certainnew and useful Improvement in Electric Signal Apparatus, of which thefollowing is a specification.

My invention has been designed particularly with reference to the needsof an automatic block system for railways, which involves the use oftrack sections electrically insulated from each other. In such a systemeach track sect-ion usuallyforms part of a constantly closed electriccircuit including a relay or other instrumentality for controlling theconnections by which the signal appropriate to that section is operatedor controlled, as shown and described for example in my Letters PatentNo. 496,786 or No. 496,787, of May 2,1893. When the track section isclear the signal stands at safety, as soon however as a train passesonto the section the track circuit is completed through the path oflower resistance aiforded by the wheels and axles of the cars, and therelay is cut out, in which event the signal goes to danger, and staysthere until the train quits the section, at which time the track circuitis restored through the relay and the signal thereby is automaticallyreturned to safety.

It quite often is the case that there may be one or more switches on atrack section for shunting trains; and it is of course desirable andindeed necessary to a complete automatic block system, that all theswitches included in any one section should be in their normal position,for a train entering that section when the signal stands at safety.Otherwise the train might run into an open switch without warning. Tothis end 'I connect to the switch-or each switch if there be more thanone-a short circuiting instrument or apparatus, which whenever theswitch to which it is connected is in the least out of normal position,will short circuit the track battery, or in other words will actprecisely as though a train or a pair of wheels and their connectingaxle were on the section. It is requisite in such an instrument that itsshort circuiting or shunting action should follow almost the slightestmovement of the switch from its normal position; that the remainder ofthe movement of the switch should not aifect or operate to change therelations of the contacts thus brought into action; and that upon thereturn movement of the switch the short circuiting action of theinstrument should not cease until the switch has practically been againset in normal position. The instrument also to be fully available forpractical use should be strong, free from complication, and certain ofoperation. These objects are realized in the instrument which I havedevised and which I shall now proceed to describe by reference to theaccompanying drawings in which Figure 1 is a plan of the instrument withthe cover removed from the box or case, to expose the working partstherein. Fig. 2 is an end elevation of the same with the end of the boxremoved. Fig. 3 is a plan and Fig. 4 is an edge view of the contactlever. Fig. 5 is a diagram showing the instrument connected up incircuit with a track section, and block system appliances therefor.

A is the box or case containing the working parts. It has on its bottoma bearing at a for the contact lever B, and a tubular bearing at a forthe spindle O, which extends through the bottom of the box, and hasfastened on its outer end the crank arm 0'. On the inner end of thespindle is made fast the smaller crank arm 0 for engaging and open atingthe contact lever. To the outer crank arm 0 is connected through themedium of the shank D jointed to the arm, the connecting rod E, which atits other end is secured to or connected with the switch points 3 (Fig.4) so as to be actuated by them.

The contact lever B has on its upper face a strip a of conductingmetal-preferably metal which does not oxidize readily-backed by a bed orlayerb of insulating material and held to the body of the lever byinsulating screws 0. The conducting face a of the contact lever playsback and forth under and out from under spring contact strips cl, cl, (Z(Z secured to an insulating base e. Two of these strips cl, (1 areconnected to one pole of the battery to be short circuited, and theother two (1, d to the other pole of said battery, the object of using aplurality of con tact strips being to insure certainty of electricalcontact between the lever and the strips. The contact lever at its outerend rests upon and is upheld by a curved rail f projecting up from thebottom of the box. This end of the lever during its movement issupported in this way and prevented from undue depression, thus insuringabsolute certainty of contact between the lever and the contact strips.The movement of the contact lever is derived from a pin or roller stud gon the small crank arm which acts for this purpose upon the prongs 7L,1', of a peculiarly shaped jaw U with which the lever is provided at apoint nearits fulcrum. The prong his short and straight throughout itslength; and it is the one which is acted on to move the lever in adirection to open the contacts. The prongt' for a short portion of itslength (the portion of its length nearest the bight of the jaw U) isstraight and parallel with the prong 7t; beyond that point it is curvedin the arc of a circle struck from the axis 0, with a radius 0, g. Thisprong serves to close the contacts, the movement of the lever for thispurpose being effected by the action of the pin g upon the shortstraight portion of its length; the pin g as soon as it reaches thecurved portion of this prong can continue its movement indefinitelywithout further actuating the lever, at the same time, through theintermediary of this curved portion, preserving its operative connectionwith the lever.

The position of the parts shown in Fig. 1 is that assumed by them whenthe switch has been moved from normal position. This movement of theswitch has pulled on the rod E with the effect of causing the pin 9 toswing to the right. In this movement it has been carried out from thejaw proper U, and in so moving has by its action on the short straightface of the prong 2', caused the contact lever to move so as to at onceclose the contacts. A very slight movement of the switch has effectedthis result. The remain-- der of its movement can take place withoutfurther disturbance of the parts, the pin 9 during this portion of itsmovement traveling over the curved portion of the prong 2'. Upon thereturn movement of the crank pin 9 (due to the return of the switch tonormal position) it will not move the contact lever until it nearlyreaches the end of its movement. At this time it will strike against theprong 7L, and thereby will throw the contact lever out from under thecontact springs, thus opening the contacts and allowing the trackbattery to reach the relay or other device under control.

This switch mechanism comprising essentially the contact strips, thejawed lever, and the crank arm, constructed and having the. mode ofoperation hereinbefore described, I term for want of a better term asnap switch. It is a switch in which the contact lever is positivelyoperated in each direction. The throw of that lever in one directiontakes place immediately upon the commencement of the movement in onedirection of the crank arm, the lever remaining unaffected during theremainder of the movement of the crank arm; and the throw of the leverin the other direction takes place during the return movement of thecrank arm, but only when the crank arm has very nearly completed thatmovement. It is a switch which has these peculiar movements that Iintend by the term snap switch the aim being to put the snap switch fromnormal the instant the track switch starts from normal, and to maintainthat abnormal position of the snap switch practically so long as thetrack switch is removed from its normal position.

One of the uses to which the instrument can be put is represented inBig. 4;. In this figure X is an insulated track section; T, 13 is thetrack battery; R is a relay in circuit with the battery-the circuitbeing completed through the rails of the track section; S is a circuitcompleted through contacts controlled by the track relay R, and intendedto control the operating of a signal; 3 is a switch; and A is myimproved short circuiting or shunting instrument electrically connectedthrough its contact strips to the track circuit, and mechanicallyconnected in the manner hereinbefore indicated to the switch points. Thetrack circuit is a constantly closed circuit which normally includes therelaythe arrangement being such that the signal when the track is clearwill stand at safety as described in my Letters Patent hereinbeforereferred to. The switch instrument A also is so adjusted that itscontacts can open when the switch is in normal position. Under thisarrangement whenever the switch points are moved appreciably from normalthe instrument A will at once be operated to close its contacts thusshort circuiting the track battery, and cutting out the relay in thesame way and with the same effect as though a train were on the section.

Having now described my invention and the manner in which the same is ormay be carried into effect, what I claim as new, and desire to secure byLetters Patent, is

1. The snap switch consisting of the contact strips and thelever-operating crank arm, in combination with the contact lever provided with the jaw U bounded on the one side by the prong 2' having ashort straight portion which is operated on by the crank arm to throwthe lever immediately upon commencement of the outward movement of saidarm, and a curved portion beyond said straight portion over which thearm travels without further affecting the lever, and on the other sideby the prong it upon which the crank arm acts only when it has nearlycompleted its inward or return movement.

2. In combination, the jawed contact lever, the crank arm for operatingthe same, the contact strips beneath which the lever moves, and theguide rail for supporting and upholding the outer or free end of thelever, substantially as and for the purposes hereinbefore set forth.

3. The box A, the spindle C with its outer and inner crank arms 0, C thepivoted jawed contact lever, the contact strips beneath which said levermoves, and the guide rail for supporting the free end of the levertheseparts being constructed and arranged together for joint operationsubstantially as hereinbefore shown and described.

4:. The combination substantially as hereinbefore set forth, of aninsulated track section, a track circuit completed through the rails ofsaid section, a snap switch interposed in said circuit, a track switch,and connections whereby the snap switch is operated by or from the trackswitch immediately the latter starts to move from its normal position.

5. The combination of the insulated track section; the constantly closedtrack circuit completed through the rails of the section and including arelay; the track switch; a snap switch interposed in the track circuit;and connections between the track switch and snap switch whereby thelatter is caused to close the track circuit through it and thus cut outthe relay whenever and as soon as the track switch begins to move fromits-normal position, substantially as and for the purposes hereinbeforeset forth.

I11 testimony whereof I affix my signature in presence of two witnesses.

JACOB WILLIAM LATTIG.

Witnesses:

M oRRIs KIRKPATRICK, H. D. MAXWELL.

